Valves are widely used in many industries for controlling fluid or other flow through a pipe or conduit. A non-return valve, also known as a one way valve, is a particular type of valve which operates by opening when the fluid is flowing in one axial direction along the pipe, allowing substantially free flow of the fluid therethrough, and by closing in response to fluid flow in a second, opposite axial direction along the pipe to prevent throughflow in that second direction. Non-return valves are used in plumbing, mechanics, hydraulics, pipelines, steamlines and many other industries that use pipes or conduits with fluid including liquid, steam or other gas running through them.
In conventional arrangements, non-return valves are generally big and bulky and often considerably reduce the bore of the pipe in which they are used. Thus, even when a conventional non-return valve is open in order to allow fluid flow in a first direction, the fluid flow is still at least partially impeded by the presence of the valve itself. Furthermore, fitting these relatively large valves can be difficult and time consuming, particularly in tight or confined spaces.
Conventional valves are generally housed within a body which has shoulders, knuckles or other features which connect to a pipe at either end. For example some non-return valves include flaps which fit onto the end of the pipes, capping the end of the pipe. These conventional valves require considerable space to be available within a pipe or other conduit in order to fit the valve therein. For example some valves include flaps or other components that need to be turned sideways or otherwise moved upon insertion into a pipe, which requires considerable space within the pipe as well as considerable user skill and effort in fitting the valve.
When a conventional valve is fitted in a pipe, it is often necessary to cut through the pipe completely in order to insert the valve therewithin. This causes the pipe to lose some of its rigidity and strength and thus has a negative effect on the life expectancy of the pipeline.
There is no known device or approach for implementing a valve, in particular a non-return valve, in a pipe in a compact and efficient manner and without significantly compromising the rigidity and strength of the pipeline.
An invention is set out in the claims.
According to an aspect there is provided an insert for providing a valve in a conduit, the insert being arranged for an insertion through an opening in a surface of the conduit, the insert comprising a body having first and second open ends defining an axis of flow therebetween. For example, the opening may be a slot cut through part of a cross section of the conduit. The insert further comprises a valve flap connected to the body, wherein the valve flap is movable between a closed position in which the valve flap creates a closure, thereby preventing flow along said axis, and an open position in which the valve flap allows flow along said axis. The valve flap is arranged so that, when it is in an open position, it is substantially U-shaped in side cross-section and is oriented with respect to the insert body so that the U-shape of the valve flap arches over the axis of flow.
Because the insert is arranged for insertion through an opening in a surface of a conduit, it can be used to provide a valve at any point along the length of the conduit, not just at one end thereof. Furthermore, because the insert can be inserted through an opening in the surface of the conduit, it is not necessary to cut through an entire cross-section of the conduit in order to place the insert and thus provide a valve therein. Therefore the integrity of the conduit can be maintained but at the same time a valve can be provided reliably in that conduit.
By providing an insert including a body having first and second open ends, defining an axis of flow therebetween, and a valve flap connected to that body and rotatable between a closed position in which the valve flap forms a closure and an open position, flow of fluid or other material can be controlled. Because the valve flap is substantially U-shaped in side-cross section when in an open position, it can be oriented to arch over the axis of flow when in that open position. Thus the valve flap is minimally invasive when in the open position and so enables increased flow.
Movement of the valve flap from the closed position to the open position can be limited to a single rotational direction only, as a result of which a non-return valve is provided. Furthermore, the cross section of the valve flap when viewed along the axis of flow and when in the closed position can be matched to the cross section of the body and/or of the conduit to form a closure, thereby making the valve reliable and leak-proof. This reliability can be improved by the provision of a seal to cooperate with the valve flap to form a closure.
At least a portion of an inner surface of the insert body can be curved, and the curvature of the U-shape of the valve in an open position can be matched to the curvature of said portion of the inner surface of the body. The valve flap can therefore sit closely against that inner surface when in an open position. Therefore the presence of the valve flap embraces the flow though the body and is minimally invasive to the cross sectional area of the body.
The valve flap may be rigid or it may be at least partially deformable. When the valve flap is at least partially deformable, it can take on a substantially planar configuration when in the closed position and can take on a substantially curved or U-shaped configuration when in an open position. The body of a deformable valve flap can include relatively rigid portions that can assist with rigidity of the valve when it is in the substantially planar, closed configuration and/or can guide deformation of the flap into a suitable shape in the open position. In its substantially planar configuration the deformable valve flap serves to provide a reliable closure within a conduit while in its deformed open position it arches over flow in the conduit, maximising the available throughflow volume therein.
According to an aspect there is provided a method of installing an insert for provision of a valve in a conduit. The method comprises creating a slot in the surface of the conduit, said slot not extending across a full cross-section of the conduit, and fitting the insert, which includes an insert body and a valve flap, via said slot. Preferably the slot extends across no more than half a cross-section of the conduit. The slot can be cut in a direction substantially perpendicular to the direction of fluid flow in the pipe.
Thus a reliable, easy to use and cost-effective solution is provided.